ABC da astronomia - Ano luz

Synopsis: Light Year may seem a unit for measuring time, but this is a standard that defines the distances between the planets and other celestial bodies in the universe. Scientists reached this far because the speed of light is considered constant: 300,000 km / s. One can say is look at the sky to see what's in the past, and in this episode of the ABC Astronomy you will understand why this statement knowing some strategies for calculating light years beyond the ways to find distances between stars .
Source: TV School.
URL: http://tvescola.mec.gov.br/tve/video?idItem=382